US1047663A - Turbine compressor or pump for elastic fluids. - Google Patents

Description

I 1. LAWAGZEOK. TURBINE COMPRESSOR OR PUMP E 'OB. ELASTIC FLUIDb.

APPLIUATION FILED MAY 22, 1911.

' Patented Dec. 17, 1912.

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[72 V621 Z 0 2-: M W. e/( by 27 A Z Z0271 By P. LAWAGZEGK. TURBINE COMPRESSOR 0R PUMP FOR ELASTIC FLUIDS.

APPLICATION nun MAY 22, 1911.

Patented Dec. 17, 19,12.

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UNITED STAClE PArENT OFFICE.

FRANZ LAWACZECK, OF AEBZEN, NEAR HAMELN, GERMANY.

To all whom it may concern Be it known that I, FRANZ LAWACZECK, a

citizen of the German Empire, residing at Aerzen, near Hameln, in the Kingdom, of Prussia, Germany, have invented certain new and useful Improvements in Turbine Compressors or Pumps for Elastic Fluids; and I do hereby declare the following to be a full, clear, and'exa'ct descriptibn of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in turbine compressors or pumps for fluids.

In compressors or blowers of the centrit ugalor turbine type, in which the pressure of the fluid at the outlet is subject to considerable variations, the volume of fluid forced through the discharge is considerably increasedwhen its pressure is reduced. This increase 'in the volume of fluid results in an increase of the energy consumed by the compressor. Furthermore, in. many cases the volume of the fluid supplied by the compressor must be constant, even if the resistance of the fluid varies. For example, where the 7 compressor is used to sup ly combustion air to-high furnaces, cupola urnaces, and other i fire places, the volume of the air must always be constant, while its pressure is of minor importance, providcd it is so high that it am always force the necessary amount of combustion air through the fuel. In order to keep under such circumstances the volume of thenir constant, regulating means, such as throttle-ialves, have been provided which were set or her manually or automatically accord ng to the resistance of the furnace or other place'gof use.

The bject of my improvements is to proyide a ompressor of the class indicated in which special regulating means are dis pensed w'th, and in which the regulation of the voiume'o'f the fluid supplied by the compressoris .efiected by the construction of the machine itself, and more particularly by the construction and arrangement of the vanes of the impeller and especially of the guiding apparatus. V

Broadly sphaking my invention consists in so constructirig the ,vanes, that upona reduction of the'gresistance of the fluid within the discharge eonduit or place of use, and therefore uponfan increase of the volume of ihe fluid'suppli'd by the compressor, the loss caused by impact ot the fluid upon its TURBINE COMPRESSOR 0R PUMP FOR ELASTIC FLUIDS.

' Specification of Letters Patent. Patented Dec. 17, 1912. Application filed May 22, 191 1. Serial No. 628,726.

- discharge from the impeller and its admission to the guide vanes and the contraction thereof xvltlnn the gulde passages are such,

that the resistance. of the fluid within the guide passages is sufliciently increased, as to prevent an undue increase in the volume of the fluid supplied by the compressor.

For the purpose of explaining the invention an example embodying the same has been shown in the accompanying drawing in which the same letters of reference have beennsed in all the views to indicate corresponding parts.

In said drawingFigure 1,'is a partial $6 section of the guide apparatus of the compressor taken perpendicularly to the axis of the compressor, and showing. two guide blades providing a guide passage for the fluid and illustrating, in adiagrammatical way, the relative speeds of the fluid entering the guide passage and of the impeller. Fig. 2, is a similar section showing the actual contraction or reduction of the cross-sectional area of the steam passing through the guide go passage caused by a decrease in the resistance and an increase in the speed of the fluid; Fig. 3, is a similar section of the impeller and the guide or diflusion apparatus,

Fig. 4, is a cross-section taken on a plane 35 I through the axis of the compressor, Figs. 5 and 6 are detail views showing the manner of securing the side wall ring on the impeller, and Figs. 7 and 8 are further views showing the manner of mounting the vanes on the impeller.

As is known to those skilled in the art, when the volume of the fluid forced by the impeller of a turbine compressor differs from that for which the vanes of the impeller and the guide apparatus and the passages formed by said vanes have been designed, a loss by impact is being caused in p the flow'of the fluid upon'the passage of the latter from the impeller to the guide apparatus. Tfthe volume is above the normal, the angle between the'tangent of the impeller and the direction of flow at which the air is discharged from the impeller is larger than that between the tangent and the vanes of the diffusion or guide apparatus. Furthermore, as is indicated in rig,. 2, the current of the fluid is contracted with in the passages of the guiding apparatus.

My invention consists 'inusing these facts,

2'. e. the loss caused by impact and the contraction of the current of fluid, for regulating the compressor. .And with this object in view my invention consists in so arranging the vanes oi the guiding apparatus, that the loss by impact and the contraction of the fluid are suflicient to hold the volume of fluid supplied by the compressor Within definite limits.

I have found, that for the same relative increase of the volume of the fluid the loss caused by the impact of the fluid at its discharge from the impeller attains its maximum, if the angle g at the inlet of the vanes of the guiding apparatus is about 45 de grees, or if tgg is about equal to 1, as appears from the following: If for the normal value of the volume of fluid the radial component of the speed of the current of air at the discharge from the impeller is o this value is increased to o (1+p), if the volume is increased p%. At the normal output the angle of the current discharged from the impeller will be c. If the output is increased 12% the increase of the said angle will be, m. The value of this increased angle is tion of (Mtge), it Will be found by difieintiation, that for the constant change of the volume of 22% this increase attains its maximum at a value of in our case p will ordinarily be a small value, because only a small variation inthe output is desired. Therefore the most favorable value of the angle at the inlet of the vanes of the diffusion apparatus is about 45, and the effect of the impact used for regulating the com ressor is so much the larger, the nearer 't c said angle is to the value of 45. Thcrefore'comparatively large radial speeds are favorable for regulating the' compressor. Thethrottling which can thus be obtained will ordinarily not be sufficient for properly regulating the output of the compressor, and it is necessary to make use bf the contraction of the current of the fluid. To make this contraction sufm and g.

Obviously the said contraction will be the same for each vane, so that the remaining area is so much the smaller, the smaller the relative distance of the vanes 1s. These conditions will readily be understood from an inspection of Fig. 2 in which a guide pas sage is shown, the direction of the current of air which enters the said passage corresponding to an increase of the output above the normal. If the air enters the said passage Without any impact, that is under normal conditions, the cross-sectional area through which the air can flow will have the value t sin. c. It the volume of air is increased, the said area will be reduced to the value 2% sin. gm,. Therefore the coetlicient of the contraction will be m g) 1 sin. If the number of the vanes is 'ijurcased and therefore the value If is decreased, for example to 4 t, the coefiicient of the contraction is increased to The derivation of 'the value m from the actual direction of the flow of the fluid or, what is the same, from the percentage of the increase of the volume above the normal output, can easily be ascertained by BXPQIl-r ment. If thereafter it is prescribed, for a certain. installation, that in case of a variation of the resistance the increase of the volume of fluid will be not more than 37 the value t which is necessary to meet this condition can be calculated from the values Experience has shown, that in turbine compressors the energy required is substantially proportional to the volume of the fluid forced by the'compressor. Therefore, when using'my improved self-regulating turbine compressor the required energy can not be increased more than 20%.

As far as practical construction of the compressor is concerned, it. willbe remembered, that ordinarily in case of fluid admission to the diflusion apparatus withoutimpactthe etliciency is'increased, if the num-' ber of the vanes is increased, because thereby whirls of the fluidare prevented. If howevertho number of the vanes is too high, the said eflicieucy will fall again by reason of the increase in the friction of the fluid on the vanes which in constructions now in use are not sufficiently smooth. Besides, it is necessary to sharpen the vanes as far as possible, if their number very large.

For this reason in my improved turbine compressor in which the number of the vanes is considerably above what 1s. now common 111 mach nes of thls class the vanes are preferably made of polished band .steel of a thickness of about i} of a millimeter, and they are-preferably bent into shape within the compressor itself by being .maloutput of the compressor and admission of the fluid into the vanes without im pact the efliciency is high notwithstanding the large number of the vanes.

To show my improved construction more in detail an example thereofhas been shown in Figs. 3 to 8 of the drawings. Though my improved construction of the vanes is particularly useful in combination with the construction of the compressor described above, I wish it to be understood, that my invention is not limited to such use, and that my improved vanes may be used in compressors of the ordinary form in which selfregulation is not aimed at.

Referring now more particularly to Figs. 3 to 7 of the drawings, the casing e and the impeller (Z are provided with annular dovetailed notches 7c and respectively within which corresponding clamping blocks a and b are fitted which are fashioned according to the curved forms of the vanes 0 and 0' of the guiding or diffusion apparatus and the impeller. The said vanes, which are made of elastic highly polished steel bands,

are bent into their proper form by being clamped between the blocks a and Zg.

Ordinarily the vanes are held lt'l position by friction. However where the speed of the impeller is high I prefer to secure the vanes against being thrown outward by centrifugal force, for which purpose I provide pins f which are passed through bores of the vanes c and with their projecting ends are engaged in notches n of the clamping blocks 6, as is shown in Figs. 7 and 8.

The clamping blocks can be manufactured at low cost and with great accuracy on molding machines. They can receive a high polish, so that the friction of the fluid flowing between the vanes is reduced to a minimum. Even for high speeds they may be made of cast iron' or aluminum, because they are not subjected to tensile strains.

If it is desired to cover the vanes a of the impeller by a ring it, as is shown in steel bands, which are secured in place by suitable clamping blocks. Thereby whirls are prevented in the passages of the impeller. a

While in the preferred form of the in vention both regulating means, a. c. regulation by impact and regulation by contraction, are provlded m the same turbine compressor, I wish it to be understood, that my invention is not limited to such combined use of both regulating means, and that inmany cases regulation either by impact or by contraction may be found sufficient. It should also be understood, that my inven: tion is not limited to a single stage blower,

or to the constructions shown in the draw-- ings. I a

Vvhile in describing the invention referful in pumps for non-elastic fluids, such as water.

I claim herein as my invention:

1. In a fluid compressor or blower of the turbine type, the combination with an im-' peller, of a guiding apparatus interposed between said impeller and the 'outlet of the compressor or blower, and provided with a plurality of guide vanes, said vanes-being arranged at such angle to lines tangent to the impeller and being located at such distance apart that in case of a decrease of the resistance at such outlet to the discharge of the fluid therefrom, the currents passing between the vanes will be contracted to afford a resistance corresponding with the resistance at such outlet.

2. in. a fluid compressor or blower of the turbine type, the combination with an impeller, of a guiding apparatus, provided with-vanes; the angle at which said vanes are inclined to the tangent of said impeller being such that a. line indicating the resultturbine type, the combination with an impeller, of a guiding apparatus, provided with vanes, each of said vanes at the inlet of the impeller being inclined at an angle of approximately t5to the tangent ofthe 1mpell'er, and the distance apart of such vanes with thin,

being such that in the case of a decrease of the resistance at the outlet of the compressor or blower, the current of fluid is retarded by impact andis contracted in passing through the passages between the vanes to such an extent as to afford a resistance corresponding with the resistance at such outlet.

4. In a fluid compressor 'or blower of the turbine type, the combination with an impeller, of a guiding apparatus, provided with curved vanes, the angle between the tangent to the impeller and the tangent to said vanes at the inlet from the said impeller being approximately 45".

5. In a fluid compressor or blower of the turbine type the combination with an impeller, of guiding apparatus, provided curved, sheet metal vanes; the curvature of and distance between said vanes being such that in case of a decrease of the resistance at the outletoi the compressor or blower the current of the fluid is contracted during its passage between said vanes to such an extent as to afford a resistance -corresponding with the resistance at such out-let.

6. In a fluid compressor or blower of the turbine type, the combination with an impeller, of a guiding apparatus, provided with curved vanes made of band steel and clamping blocks having curved clamping faces between which the side margins of said vanes are confined and by which the I arranged at an angle to lines tangent to the impeller and located at such distance apart that in case of a decrease of the resistance at such outlet to the discharge of the fluid therefrom, the currents passing between the vanes will be contracted to afford a resistance corresponding with the resistance at such outlet.

In testimony whereof I aflix my signature in presence of two witnesses.

FRANZ LAVVACZECK.

Witnesses:

ERNEST C. OBERHoL'rzEn, MARTHA L. THOMPSON.

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